- SYNTHESIS AND PROPERTIES OF C-1-AZIDO-ABA
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The acyl azido derivative of ABA has been synthesized in high yield via a mixed anhydride.It is stable in most organic solvents but rearranges in water (t1/2 of 30 min at 30 deg C) to yield 1'-hydroxy-4'-oxo-α-ionone, presumably via an isocyanate intermediate.Photolysis of (+/-) RS-azido-ABA in a 1percent solution of bovine serum albumin with low intensity UV254nm light gave labelled bovine serum albumin (BSA).Racemic 1-azido-ABA inhibited wheat embryo growth with about 10percent the efficacy of racemic ABA.Racemic 1-azido-ABA was resolved into its enantiomers on a chiralcel HPLC column and both enantiomers were bioassayed.The (+)S-enantiomer caused stomatal closure and inhibited growth of Lemna gibba with about 10percent of the potency of ABA but the (-)R-enantiomer was inactive in both the stomatal closure and Lemna gibba bioassays.It is suggested that in one of the two canonical forms of the azide the α-nitrogen atom carries the negative charge in the same position as the carboxyl group of ABA and so is able to substitute for it. Key Word Index: Abscisic acid; indole acetic acid; gibberellin; azide; bioassay; photoaffinity labelling; receptor.
- Willows, R. D.,Milborrow, B. V.
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- Synthesis of 2-fluoroabscisic acid: A potential photo-stable abscisic acid
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Novel fluorinated abscisic acid (ABA) analogs were synthesized by introducing fluorine through the Wittig reaction of α-ionone derivatives with triethyl phosphono-2-fluoroacetate. Molecular orbital calculations showed that the introduction of fluorine at the 2 position stabilized the configuration of the side chain.
- Kim, Bum Tae,Min, Yong Ki,Asami, Tadao,Park, No Kyun,Kwon, Oh Young,Cho, Kwang Yun,Yoshida, Shigeo
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p. 1797 - 1800
(2007/10/03)
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- Norisoprenoids in Vitis vinifera White Wine Grapes and the Identification of a Precursor of Damascenone in These Fruits
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Twenty-four norisoprenoids, which are either free volatile components of juices of Vitis vinifera cvv.Chardonnay, Semillon and Sauvignon Blanc, or are liberated by glycosidase enzyme, or acid hydrolysis of extracts of these juices, have been identified.Eleven of these norisoprenoids are reported as grape products for the first time.The hypothetical 7-oxomegastigmane precursors, grasshopper ketone (5) and megastigm-5-en-7-yne-3,9-diol (10), as well as the related allene, 9-hydroxymegastigma-4,6,7-trien-3-one (6), have been observed for the first time, cooccurring with damascenone (1), 3-hydroxy-β-damascone (2), 3-oxo-β-damascone (3) and 3-oxo-α-damascone (4).Hydrolytic studies have shown that megastigm-5-en-7-yne-3,9-diol (10) is a precursor of damascenone (1) and 3-hydroxy-β-damascone (2) during wine conservation.
- Sefton, Mark A.,Skouroumounis, George K.,Massy-Westropp, Ralph A.,Williams, Patrick J.
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p. 2071 - 2084
(2007/10/02)
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- METABOLISM OF ABSCISIC ACID: BACTERIAL CONVERSION TO DEHYDROVOMIFOLIOL AND VOMIFOLIOL DEHYDROGENASE ACTIVITY
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A species of Corynebacterium, capable of metabolizing abscisic acid (ABA), was isolated from soil.The organism converted ABA to dehydrovomifoliol as the major metabolite.A cell-free extract exhibited vomifoliol dehydrog
- Hasegawa, Shin,Poling, Stephen M.,Maier, V. P.,Bennett, Raymond D.
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p. 2769 - 2772
(2007/10/02)
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- Photochemische Reaktionen. 122. Mitteilung. Zur vinylogen β-Spaltung von Epoxy-enonen: Photoisomerisierung des 3,4:5,6-Diepoxy-5,6-dihydro-β-jonons
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On 1n,?*-excitation (λ>347 nm), 3,4:5,6-diepoxy-5,6-dihydro-β-ionone ((E)-3) shows the typical behaviour of α,β-unsaturated γ,δ-epoxy ketones furnishing the (Z)-enone 3 and by C(γ),O cleavage of the oxirane the dihydrofuryl ketone 10
- Bischofberger, Norbert,Weck, Guy de,Frei, Bruno,Wolf, Hans Richard,Jeger, Oskar
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p. 1766 - 1776
(2007/10/02)
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